Circuit interrupter



J. M. WALLACE ETAL May 3, 1949.

CIRCUIT INTERRUPTER Original Filed June 24, 1941r -ea H: 171

Patented May 3, 1949 CIRCUIT INTERRUPTER J ames M. Wallace, Braddock,Herbert L. Rawlins, Swissvale, and James M. Cumming and Wayne S. Aspey,Turtle Creek, Pa., assignors to Westinghouse Electric Corporation, EastPittsburgh, Pa., a corporation of Pennsylvania riginal application .lune24, i941, Serial No.

399,452., Divided and this application November 1, 1944, Serial No.561,384

.4 Claims. l

This invention relates to electric circuit intere rupters in general,and more particularly to operatingmeans for such interrupters.

This invention is a division o the subject mat oi' our copendingapplication on Circuit interrupters, Serial No, 399,452, l'iled June 24,194i,

assigned to the same assignee of this invention.

The specic disclosure hereinafter given oi this invention is embodied inan automatic reclosing circuit breaker having separable contacts andctromagnetic means for separating the concts, and with the contacts andcontact-actuing mechanism all suspended in a container :nom thecontainer cover.

@ne object of this invention is to provide novel means for readilyremovably supporting the electromagnetic operating coil.

Another object of this invention is to provide a novel assemblage of theoperating mechanism for an automatic reclosing circuit breaker of thetype described which will permit changing of the rating of the breakerin a relatively simple manner.

Still another object of this invention is to provide a novel unitaryassembly with the cover of a circuit breaker casing, of the breakercontacts, and contact-actuating mechanism.

These and other objects of this invention will become more apparent uponconsideration of the following detailed description of a preferredembodiment thereof, when taken in connection with the attached drawing,in which:

Figure 1 is a substantially central vertical section through a circuitbreaker embodying this invention with certain parts thereof shown inelevation;

Fig. 2 is a partial elevational View of the operating mechanism shown inFig. l;

Fig. 3 is a transverse sectional view of the breaker shown in Fig, 1taken substantially on the line III-III thereof with certain partsomitted;

Fig. 4 is a fragmentary sectional view of the lockout integratingmechanism employed in the breaker shown in Fig. 1;

Fig. 5 is a view like Fig. 4 but showing the parts of the mechanism ina. diierent position from that shown in Fig. 4; and

Fig. 6 is also a partial sectional view illustrating the mechanism ofFigs. 4 and 5 in a still diierent position of the parts thereof.

The circuit breaker constituting this invention is shown by way ofexample as being mounted in a tubular insulating casing 2 which may beof any desired insulating material, preferably porcelain or the like.The casing 2 is provided with .a closed bottom and an open top, with thetop being closed by a cover assembly fl, and the bottom of the casinghavin-g associated therewith a terminal assembly 6. Intermediate theends of the casing 2 there is provided a cylindrical surface 8, and asupporting bracket l2 is adapted to be clamped around this cylindricalsurface with resilient material Ill interposed between the clamp l2 andthe outer casing wall to prevent damage thereto.

The terminal assembly 6 at the bottom of the casing includes a terminalbolt I4 of conducting material adapted to extend through a substantiallycentral aperture in the bottom casing wall, and the bolt is providedwith an enlarged head i@ interiorly of the casing, with packing material2li interposed between the head I8 and the bottom wall of the casing. Anut 22 and washer 24 co-operate with bolt I4 to retain the same inposition, and a conductor 28 may be secured to 'the bolt, for example,as by a second nut 2S. Bolt I4 is preferably provided Wtih asubstantially central bore 30 for the purpose of draining casing 2, thelower end thereofbeing adapted to be closed by a screw threaded closureplug 32.

The upper end of casing 2 is ribbed, and a supporting flanged ring 34 isadapted to be secured to this ribbed portion of,4 the casing, forexample, as by cast metal, or the like, 36. Supporting ring 34 isadapted to have cover assembly 4 secured thereto in any desired manner,not shown.

The casing and terminal structure 6 described above are substantiallyidentical with those more particularly described and claimed in thecopending aplication of J M. Wallace and H. L. Rawlins,

Serial No, 374,686, tiled January 16, 1941, and in their Patent No.2,318,421, issued May 4, 1943, both of which are assigned to the sameassignee as this application.

Cover assembly 4 comprises an integral casting having a flange 38 formedintegrally with the lower end thereof and, adapted to seat on the upperend wall of casing 2 and extend over the interior of the casing. Flange38 is also provided with integral outwardly extending ears (not shown)adapted to be bolted to ears formed on supporting ring 34. The coverassembly casting is provided with a hollow portion including the topwall 4I), side walls 42, 43, and end walls 44 and k45, with the bottomof the hollow portion being open and located over the open top of casing2. At one upper corner of the hollow portion of cover assembly 4, aninclined wall is provided with a threaded aperture for co-operation witha threaded filler plug 4B, by means of which casing 2 may be filled withan arc extinguishing iluid. Top wall 4U of the hollow portion of thecover assembly is extended beyond the hollow portion and slightlyinclined downwardly as at 48 to form the top wall of a sleet hoodportion having side walls 52 and 53. The top wall 48 of the hood portionterminates in an angularly downwardly extending lip 50, for a purpose tobe hereinafter described.

As appears from Figs. 1 and 3 of the drawing, ange 38 of the coverassembly 4 has portions which extend over the open top of casing 2, andthese portions are adapted to insulatingly support the circuit breakercontacts and operating mechanisrn, for example, as by the tubularinsulating spacer sleeves 54. The spacer sleeves 54 have the oppositeends thereof threaded for co-operation with screws 56 and 58, to securethe spacers to ange 38 and the upper leg |06 of a U-shaped supportingframe $0, respectively. -The other leg i113 of U-shaped frame 60 issecured to one end of a generally rectangular frame 64, and the otherend ci this frame is preferably formed integral with the top cap 66 ofan interrupter interrupter chamber 6E includes an inng tube 'l0 or"fiber or the like, having one eaded into top cap 66, and having the iend threadedly received in a bottom ter-s l rop cap 86 is provided witha. subally central aperture 89 for closely slidably a with spaced outletapertures la adapted controlled by a sliding valve plate |ll2, ncrced bya coil compression spring |04 inte nt with the adjacent end ofinsulating The lower end cap 14 ci the interrupter rr is provided withinlet passages l, and

.ibstantially centrally located threaded for receiving the threaded endor' an `just-cle fixed contact 18 which is secured in ositicn, forexample, as by a lock nut 80. The i end of end cap 14 is reduced in sizeto form shoulder d?. on which is seated one end of a impression spring84, with the other end of spring hearing against the head i8 of ternalbolt il. Spring 84 should be of some good resilient conducting material,such, for example, as a cooper alloy or the like.

The lower end of Contact piston rod 12 is pro- 'ed with a socket forreceiving the upper end of act rod 86, secured in the socket, forexample, a rivet 83. The lower end of contact rod is enlarged to form acontact head 90. A liquid directing piston 92 is provided with a centralaperture 9| so that the piston may be slidably mounted on Contact rod 86for movement between contact head 90 and the lower end of Contact pistonrod 12. The lower end of contact piston rod 12 is counterbored toreceive a coil compression spring 93 which normally operates to biasliquid directing piston 92 towards contact head EE. As shown, piston 92is provided centrally with hollow portion to which access is obtained bymeans of a plurality of top apertures 94, and single lower aperture 95concentric with contact head 9|! so as to form an annular liquid passagetherewith. Liquid director piston 92 may have a peripheral slot for thereception of piston ring d6 to prevent leakage of liquid between thepiston and inner wall of tube 1U. A stop ring 98 is secured in positionbetween the lower end of insulating a contact rod 12, and the cap isalso tube 1l and lower end cap 14 and. as shown, projects inwardly so asto form a stop for liquid director piston 92, :o that when the contactsare closed, the piston is maintained in a position intermediate thelimits of its movement on contact rod Il. The inlet apertures 'Il in cap14 are adapted to be controlled by a check valve plate Ill freelymounted between the end wall of end cap 14 and stop ring 9|. 'I'helnterrupter chamber Il described above is substantially identical withthat described and claimed in the above-mentioned copending applicationof J. M. Wallace and H. L. Rawlins, Serial No. 374,686, except that inthe interrupter chamber herein described, valve plate |02 is springbiased in one direction, rather than being frictionally associated withcontact piston rod 12 as in the said copending application.

The operation of the interrupter chamber herein disclosed andillustrated is substantially the same as that in the above-identifiedcopending application and comprises, brieily, utilization of fluidpressures generated by a-n arc drawn, to obtain contact separation. bythe instant structure, because it will beobserved that as soon ascontact piston rod 12 is moved upwardly and contact head 90 moves out ofengagement with iixed Contact 18 to strike an arc, the action of such anarc on the same extinguishing liquid within the chamber, such, forexample, as oil or the like, will decompose the same to generate a gaswhich will build up a pressure within chamber 68. As soon as thispressure builds up, it will obviously force check valve plate IM andvalve plate iii! outwardly relative to insulating tube 10 to close boththe inlet and outlet apertures 16 and 13, respectively. Gutward movementof valve plate |02 readily occurs because the upper side of this plateis vented by aperture |03. Accordingly, such pressures within thechamber will act on contact piston rod 12 in a piston-like manner toforce the same to move outwardly of the chamber, and thereby increasethe contact separation. In the upward movement of contact rod 85, liquiddirector piston 82 remains stationary until contact head engages theupper wall of the director tc thereby draw the arc out to an optimumlength before moving the director to cause a how of liquid throughapertures 94 and 95 and into the arc to extinguish the same. Contactpiston rod 12 and contact rod t6 will be moved outwardlg,T by thepressure developed within arc chamber 88 until the combined action ofattentuation of the arc and ilow of liquid therethrough causeextinction. As soon as the arc is extinguished, the contact piston rod12 is adapted to be moved downwardly towards fixed contact 18 in amanner to be hereinafter further described, and since pressure is nolonger being generated within. the chamber, spring H34 will be freeto'move valve plate |02 downwardly to open outlet passages 13 and permitexhaust oi' gases and used liquid out of the upper end o! the arcchamber. This upilow of gas and used liquid from the chamber will betaken care of by an inflow of fresh liquid through inlet apertures 16,which will cause check valve plate |00 to be unseated due to thepressure at the bottom of the casing because of the head of liquidtherein, and especially because of the difference in pressure due to thedifference in the head of liquid between inlet apertures 16 and outletapertures 13. Consequently, it can be seen that the fluid pressuredeveloped by the are is utilized in this interrupter to obtain contactThis ls accomplished separation, and that during a closing operation ofthe breaker contacts, the used arc extinguishing fluid within thechamber is replaced by fresh fluid from casing 2,

As previously stated, the substantially U- shaped supporting framemember 60 is secured to the upper end of rectangular supporting frame64, and the frame member 60 is for the purpose of supporting a solenoidcoil H2. The upper and lower legs |06 and |08 of supporting member 60are connected by spaced integral legs ||0 positioned at one sidethereof, so that the solenoid coil ||2 may be assembled with support 60by merely slipping the entire coil between legs |06 and |08 through theopen side of support 60. The legs |06 and |08 of the U-shaped frame 60are provided with aligned apertures adapted to coincide with the centralbore provided in solenoid coil ||2, and a securing sleeve or core guidetube II4, of insulating material, is adapted to be inserted through theaperture in leg |08 of the U-shaped support 60 into engagement with ashouldered plug IIB seated against a shoulder provided about theaperture through leg |06 of U-shaped supporting frame 60. Securingsleeve |4 is maintained against movement downwardly from the supportingframe 60, as viewed in Fig. 1, by the connection of rectangular frame 64thereto, inasmuch as the end plate |I8 of this frame is provided with ashouldered aperture, with the adjacent. end of securing sleeve I I4seated on the shoulder of this aperture to prevent movement thereof withrespect to U-shaped frame 60. Frame 60 is of magnetic material to form astationary frame for coil ||2 as well as a support therefor. Rectangularframe 64 is secured to the lower leg |08 of U-shaped frame 60, forexample, as by screws 62, or the like. It will be noted that solenoidcoil I2 is provided with a plurality of taps ||9 which are connected todifferent sections of the coil, and located away from the conneptinglegs ||0 of the U-shaped support 60, at the open side thereof so as tobe readily accessible for the purpose of changing the coil connectionswhen desired. Rectangular supporting frame 64 is provided with the sideplates |20 integral with top plate I8 at one end thereof, and with topcap 66 for the interrupter chamber at the other end thereof.

The upper end of contact piston rod 12 is peripherally grooved as at |22to form a notch and a latch projection |24 at the upper end thereof, forco-operation with a latch lever |26. The latch lever is adapted to bepivotally mounted on top end cap 66 of the interrupter chamber, forexample, as by a pivot pin |26, and a coil spring |30 is wound aboutpivot pin |28 with the ends thereof engaging end cap 66 and latch lever|26, respectively, for biasing the latch lever in a clockwise directionabout its pivot, as viewed in Fig. 1. The latch lever is provided with aplurality of latch lugs |32 and |34 for co-operation with the latchprojection |24 on the upper end of contact piston rod 12, and with thecore of solenoid coil ||2. A contact operating rod |36 is rigidlysecured to contact piston rod 12 and extends from the upper end thereofthrough a sleeve |31 extending through the central opening of solenoidcoil ||2 and securing sleeve ||4. The lower end of sleeve |31 isenlarged as shown at |38 to receive the upper end of a coil compressionspring |44, with the lower end thereof bearing against the bottom wallof a tubular solenoid core member |40. The tubular solenoid core |40,which is of magnetic material, has the bottom wall thereof apertured tobe slidably mounted on contact operating rod |36, and has adjacent theupper end thereof a peripheral inwardly extending rib |42 of a size toclosely engage the outer surface of enlarged portion |38 of sleeve |31.Adjacent the lower end of solenoid core |40 are radially directed ventapertures |46, for a purpose to be hereinafter described.

In the operation of the mechanism thus far described, it will beapparent that upon the occurrence of predetermined circuit conditions,solenoid coil ||2 will become sufficiently energized to attract core |40and cause it to move upwardly on operating rod |36 and compress spring|44 between the core and sleeve |31. Furthermore, because of the closeiit between core |40, securing sleeve ||4 and enlarged portion |38 ofsleeve |31, and since these parts are all immersed in the arcextinguishing iiuid, it will be obvious that upward movement of core |40will be relatively slow because of the necessity of displacing the iiuidwithin securing sleeve I4 through the relatively small clearance betweenthe core and sleeve. However, after sufficient movement of the coreupwardly so that rib |42 clears the upper end of enlarged sleeve portion|38, there will then be a relatively large annular passage through core|40 and outlet apertures |46 for liquid entrapped in securing sleeve H4,so that further movement of core |40 upwardly will take place at a.relatively rapid rate. During this rapid movement of the core, thebottom wall thereof will engage the lower end of enlarged sleeve portion38 to cause movement of the sleeve upwardly with the core, andengagement of the upper end of the sleeve with shoulder |41 formed onContact operating rod |36, will thus quickly separate contact head 90from fixed contact 18. This movement of contact head 90 by solenoid core|40 away from fixed contact 18 need be but a small amount, because assoon as the contacts are separated sufliciently to draw an arc, thepressure generated by such an arc operates to increase the contactseparation sufficiently to extinguish the arc. Obviously because of thesliding connection of solenoid core 40 with respect to contact operatingrod |36, the contact operating rod and contact head 90 are permitted tohave a considerable overtravel independent of solenoid core |40 inresponse to pressures built up within the interrupter chamber 68. Assoon as the arc is extinguished and the pressure drops withininterrupter chamber 68, contact operating rod |36 is permitted to movedownwardly to reclose the contacts. However, its downward motion ishalted by engagement of latch projection |24 at the top of the contactpiston rod 12 with upper latch lug |32. In the meantime, solenoid core|40 returns very slowly under the` biasing forces of gravity and spring|44, to the position shown in Fig. 1, because of the dashpot actionthereof in securing sleeve ||4, so that considerable time must elapseuntil the solenoid core |40 moves down into engagement with the upperend of latch lever |26, and thereby causes counterclockwise rotation ofthe latch lever to disengage its upper lug |32 from contact piston rodprojection |24. This permits the projection |24 to drop down slightlyvwith contact operating rod |36, and into engagement with the lower lug|34 on latch lever |26, where it is held until further downward movementof solenoid core |40 causes further counterclomwise movement of thelatch lever until projection |24 is released from lug |84, whereupon thecontact head is permitted to move into engagement with xed contact 18.In-

1 cldentally, it will be noted Vthat upper lug |32 of latch lever |28serves as the support for preventing undue downward movement of solenoidcore |40.

The reason why a plurality of lugs |12, |34 are provided on the latchlever to successively halt downward movement of contact head 80 towardsnxed contact 18 is that it is necessary to maintain the contactsseparated, during the time delay period before reclosure, a sufiicientdistance apart so that the dielectric therebetween will be capable ofsafely withstanding circuit voltage. Because of contamination anddeterioration of the dielectric on the interruption of high currentarcs, this distance is quite large. On the other hand, it is desired tomake the time delay between a circuit interrupting operation and areclosure of the circuit as long as possible with the available timedelay means including the dashpot comprising solenoid core |40 andsecuring sleeve ||4. Lug |32 on the latch lever, therefore, ispositioned to engage the moving contact to hold it separated from fixedcontact 18 a distance corresponding to the safe gap therebetweenaccording to the dielectric being used. If lug |34 were not alsoprovided on the latch lever, then the time delay between a circuitinterrupting operation and a reclosure of the breaker contacts would betoo short, and accordingly, to lengthen this period, the second lug |34is provided for momentarily delaying reclosure of the breaker contactsafter release of the moving con tact from lug |32, to thereby obtain alonger time delay in reclosing without undue danger of flashover,inasmuch as the period of time which lug 534 operates to maintain thebreaker contacts separated is so short that ionization of the pathbetween the breaker contacts does not have time to be completed prior toreclosure of the contacts. Also on interruption of low currents, thepressure may be insumcient to move contact projection i 24 as high aslatch lug |32 and since the dielectric will not be unduly impaired bylow current interruptions, engagement with latch lug H34 will provide asafe gap between the contacts while using full time delay on reclosure.

The upper end of contact operating rod |36 is pivotally secured as bypivot pin |50 to one end of a pair of insulating links |48, with theother ends of the links being connected to an angled crank lever |52,for example, as by the pivot pin 53. Crank lever |52 is pivotallymounted at its other end on a shaft |54 extending across the hollowportion of the top cover casting, and its outer ends are mounted inapertures provided in the side walls 42 and 43 of the cover hollowportion, with the outer ends of these apertures being closed by screwplugs |58 to prevent relative endwlse `movement of shaft |54. Angledcrank lever |52 is rotatably mounted on shaft |54, and a generallyU-shaped yoke |58 has the leg portions thereof also rotatably mounted onshaft |54, with one leg of yoke |58 pivotally connected to one end oftoggle links |60, and the other ends of these toggle links beingpivotally connected to a toggle lever |68, which is, in turn, secured onthe squared end of a shaft |88 rotatably mounted in an angled portion ofend wall :i5 of the cover assembly in a bearing sleeve |12, by a bolt|10, which also acts to secure an operating handle |14 to the othersquared end of shaft |88. Operating handle |14 is provided at the outerend thereof with a hook eye aperture |16 for the reception of a hookstick or other operatingr member. Actuating handle |14 is lim- 8 ited inits movement in a counterclockwise direction by a stop screw |18 whichmay be aecured in an adjusted position, forlexample, as by a lock nut|80.

A pair of concentric coil springs |82 and |84 are provided about shaft|54 within the hollow portion of the cover assembly 4, with one end |86ofthe outer large diameter coil spring |84 engaging flange 88 of thecover assembly, and the other end |88 thereof engaging the connectingportion |89 of yoke |58, to thereby bias the yoke for movement aboutshaft |54 in a counterclockwise direction. This movement of the yoke isnormally prevented by virtue of the toggle formed by links |50 and |88being below their deadcenter position when actuating handle |14 is inengagement with stop screw |18. One end |88 of the smaller diameterinner coil spring |82 is extended to engage the angled portion of cranklever |52, and the other end of this spring a'so engages the connectingportion |88 of yoke |58, so that when the yoke is locked by togglelevers |60 and |56 against movement in a counterclockwise direction,biasing spring |82 will operate to bias crank lever |52 downwardly or ina clockwise direction relative to shaft |54, to thereby bias contactactuating rod |38 and contact head 90 downwardly, and cause engagementof the contact head with fixed contact 18.

The circuit through the interrupter herein disclosed extends from aterminal bracket |84 secured to the top cover assembly, for example, asby a screw |98 with the bracket having a terminal socket |96 for thereception of a line conductor, through the cover casting, by way of aconductor 200 to one tap ||9 of solenoid coll H2, through the coil,conductor 202 to contact piston rod 12, contact rod 86, contact head 9h.fixed contact 18, end cap 14, compression spring 84, terminal bolt 4, toanother line conductor 28. Thus, it can be Seen that the solenoid coil|2 is connected in series in the circuit including the breaker contacts,and as shown, the whole coil is connected in series, inasmuch as the endtaps of the coil are used, and, therefore, the connection is for thelowest rating of the breaker which can be obtained with the coilemployed, inasmuch as the maximum flux generating capacity of the coilis employed to thereby obtain suillcient force to separate the contactson relatively low currents. To obtain higher current ratings, it wouldbe merely necessary to connect conductor 202 or 200 to other taps i8 ofthe coil to utilize smaller portions of the coil winding. It will benoted that the entire circuit breaker mechanism including the breakercontacts and interrupting chamber are supported as a unit with thecasing cover assembly 4, so that they may be removed with the cover fromthe casing when desired by merely unfastening the securing means of thecover to support 34 on the casing. Another feature of the particularsupporting means for the circuit breaker mechanism iliustrated is thespecific support of the solenoid coil permitting ready replacementthereof by another similar coil, or by a coil having a different numberof turns to thereby change the available ratings of the breaker. Inorder to remove coil H2, it is merely necessary to remove screws 52holding U-shaped frame 60 and rectangular frame 64 together. Thispermits securing sleeve ||4 to drop downwardly out of U-shaped frame 60,and then by removing one pivot pin. for example, the pivot pin |50, theentire contact operating rod and sleeve |31 can be slipped out ofU-shaped frame 80 through apertures in legs |08 and |08 of the frame,whereuponl coil Il 2 may be slipped laterally out of the open side of U-shaped frame 60. To insert a new coil, it is simply necessary to slideit in the open side of U- shaped frame 80 until the bore therethrough isaligned with the apertures in legs |06 and |08 of the frame,whereuponcontact actuating rod |36 and securing sleeve ||4 may beinserted through the apertures and through the bore in the coil, andrectangular frame 64 secured to the lower leg |08 of the U-shapedsupporting frame to thereby firmly secure the solenoid coil in operativeposition. Consequently, in order to remove the coll. it is onlynecessary to remove two screws 62 and one pivot pin |50.

The operation of contact biasing spring |82 mounted on shaft |54 incover assembly 4 is believed to be ,obvious from the foregoing. In otherwords, when the circuit is interrupted by energization of solenoid coil||2 suiilciently to raise core and separate the contacts against thebias of spring |82, .this spring will be effective as soon as thecircuit is interrupted to move the contact operating rod and contacthead 90 downwardly towards lxed contact 18, until projection |24 oncontact piston rod 12 is engaged by latch lug |32, whereupon reclosureof the contacts will be delayed until the latch is released by solenoidcore |40 in the manner previously described.

In the event an overload occurs on the circuit which is notself-clearing but continues after a predetermined number of successiveinterrupting operations, there is provided means for tripping the togglewhich normally prevents rotation of yoke |58, so that spring |84 becomeseiiective to rotate the yoke in a counterclockwise direction to thedotted line position shown in Fig. 1, and, consequently, raise cranklever |52, by engagement of the cross bar |88 of the yoke with aprojection |9I on the lever, together with contact actuating rod |36 andcontact head 80 to a position wherein the contact head is maintained outof engagement with fixed contact 18, because coil spring |82 will beineffective to reclose the contacts. The means for tripping the toggleincludes a cylindrical tube 204 threadedly mounted in the upper leg |06of U-shaped support 60, and provided with an inlet aperture 208 in thebottom wall thereof controlled by a ball-check valve 2|0 to permit ow ofliquid into tube 204, but preventing outflow of liquid. A piston member206 is slidably mounted within cylindrical tube 204,

Yand the upper end thereof is provided with a plurality of spacedperipheral grooves 2|4, 2| 6, and 2|8, respectively, to form aratchet-like portion on the piston accessible through a side opening 2|2 in the cylindrical sleeve 204. A pawl guide rod 220 is also secured toleg |06 of U-shaped support 60 between cylindrical sleeve 204 andcontact operating rod |36, for guiding a substantially U-shaped pawlmember 222, having the connecting portion thereof slotted, as shown at224 to receive the contact operating rod, and with the ends of the slotextending into the legs of the U-shaped pawlbut reduced in width, asshown at 226, to more closely lit guide rod 220.

lower leg of U-shaped pawl 222 to normally Contact actuating rod |36 isadapted to extend spring 230 engaging between washer 228 and themaintain the pawl in the position shown in Fig. 4.

In the operation of the circuit breaker, it will be observed that eachtime solenoid core |40 is drawn upwardly to open the circuit and engagethe lower end of enlarged portion |38 of sleeve |31 to move the sameupwardly, that it will cause a tilting of pawl 222 against the bias ofspring 230, so that continued upward movement will move the entirepiston upwardly and thereby unseat ball-check valve 2| 0 and cause apredetermined amount of liquid to be drawn in the lower end of sleeve204. As soon as the circuit is interrupted, and the contactactuating rodand associated parts are moved downwardly by biasing spring |82 in themanner previously described, compression spring 230 on guide rod 220 isoperative to withdraw the upper leg of pawl 222 from the notch 2|4 inpiston 206, so that the piston remains at the position to which it hasbeen moved, while the contacts are reclosed. Now if the fault on thecircuit has been removed, piston 206 will gradually sink to the positionshown in Fig. 4 by displacement of the liquid below the piston throughthe relatively small clearance between the piston and cylindrical sleeve204, so that eventually it will attain its original position shown inFigs. 1 and 4. However, in the event the fault in the circuit has notcleared upon the rst reclosure of the breaker contacts, they will againbe opened by solenoid ||2, and this timel pawl 222 will engage notch 2|6in piston 206, as shown in Fig. 5, inasmuch as the piston will not havehad time to sink to its original position and the piston will be movedupwardly to the position shown in Fig. 6 of the drawing. As soon as thearcis extinguished, the contacts will again be reclosed by biasingspring |82, and if the fault has cleared, piston 206 will again slowlysink to its original position as before. However, if the fault has notcleared before piston 206 has an opportunity to sink much below theposition shown in Fig` 6, the contacts will again be opened, and thistime pawl 222 will be pivoted into engagement with the lower notch 2|8in piston 206 and cause the same to be moved upwardly a further amountand into engagement with the knee of the toggle formed by levers |60 and|66 to move the knee of the toggle over-center, thereby releasing spring|84 and permitting the same to rotate yoke |58 and move the togglelevers and contact operating rod to the dotted-line position shown inFig. 1 of the drawing, wherein the breaker contacts are maintained byspring |84 in an open circuit position.

It will be observed that ordinarily actuating lever |14 is maintainedentirely within the hood formed integral with top cover assembly 4, butupon tripping of the toggle constituted by levers |60 and |66, theactuating lever |14 will be moved in a clockwise direction about itspivot axis |10 to project below the hood, and thereby give a readilyvisible indication of the fact that the breaker contacts are nowmaintained in an open circuit position. When piston 206 has tripped thetoggle, it will be observed that since contact operating rod |36 ismaintained in an upper position, pawl 222 will be maintained inengagement with notch 2|8 on piston 206 to maintain the piston in itsuppermost position. Accordingly, when it is desired to manually reclosethe breaker contacts by movement of operating lever |14 in acounterclockwise direction to reset the toggle levers to the positionshown in full lines in Fig. 1, it will be observed in the iirst place,that in the event it is thus attempted to close the circuit while anoverload is present, the breaker is trip-free in that it is free to openagainst the bias of contact biasing spring |82 irrespective of theposition of actuating lever |14. In the second place, it will be notedthat since piston 200 has had but a little time to move downwardly fromits outermost position with respect to cylindrical sleeve 204, that inthe event the breaker is reclosed manually upon an overload in thecircuit, that on the consequent circuit interruption and movement of thecontact operating rod and associated parts upwardly, pawl 222 will becaused to engage the lower notch 2 i8 of piston 20E to thereby move thetoggle overcenter and again permit spring |84 to maintain the contactsin an open position.

Thus, it can be seen that the circuit breaker herein disclosed iscapable of automatically opening the circuit with an inverse timecurrent characteristic due to the dashpot action of core |40 in securingsleeve i4, and yet the contacts are separated with a relatively fastaction due to the venting of the dashpot formed by core |40 and sleeveH4 adjacent the end of its stroke. This feature is the invention of J.M. Wallace and is more particularly disclosed and claimed in hiscopending application Serial No. 399,453, illed June 24, 1941, nowPatent No. 2,333,604, issued November 2, 1943, to the same assignee ofthis invention. Following a circuit interrupting operation, the breakercontacts are'automatically reclosed with a time delay also due to thedashpot action of core |40 and sleeve |14, while maintainingsubstantially to adjacent the end of the timed period a safe gap betweenthe breaker contacts. Also, in response to a predetermined number ofclosely successive circuit interrupting operations, novel means areprovided for maintaining the breaker contacts in an open position, whichincludes a biasing means normally held inactive by a toggle'i'vhich ismoved overcenter by a piston actuated a predetermined amount upon eachinterrupting operation. The arc chamber herein disclosed is providedwith an outlet valve which is positive in operation, and theelectroresponsive solenoid contact opening means is supported in amanner to render the same readily replaceable, and is provided with aplurality of taps so that the rating of the breaker may be readilychanged. The specific arrangement of the contact closing spring and thespring for maintaining the contact separated is especially importantwith respect to space considerations and efficiency of operation.

An operation counter 234 is adapted to be mounted on the end wall 45 ofthe hollow portion of cover assembly 4 and to be located be- Death thehood portion thereof so as to be readily visible from the exterior ofthe breaker while protected from the elements by the hood. Thisoperation counter may be of any well known type provided with anactuating crank lever 23B, mounted on an operating shaft extendingthrough the angled portion of wall 45 like shaft |68, and with crank 236pivotally connected to an operating link 238, which, in turn, isconnected to pawl 222, so as to actuate the counter on each circuitinterrupting operation of the breaker. The connecting link 238 isprovided with an insulating portion 240 to insulate the counter frompawl 222.

There is preferably provided within the hollow portion of cover assembly4, in a socket 242 provided therefor on top wall 40, a lightningarrester assembly, which may be of any well known type includingelectrodes 256 spaced by an insulating plate 258 to form a gap in serieswith a porous block 260, in the circuit between top wall 40 of the coverand terminal 244 oi the assembly. A tubular insulating sleeve 262.l ispositioned between the assembly and the side wall of socket 242, andinsulating disk 210 supports terminal 244 and is secured to the coverassembly 4 by screws 26E, with a sealing gasket 204 therebetween tomaintain the arrester assembly in socket 242. A shunt 260 connectsterminal 244 and a contact plate 21|, and this plate is maintained incontact with block 260 by a spring 212. The arrester terminal 244 isconnected by conductor 248 to the top leg |06 of U-shaped frame 60 tothereby form a circuit by-passing solenoid coil ||2. This obviously willprevent the solenoid coil from opening the breaker contacts in responseto surges inasmuch as the coil will cooperate with the shunt circuitthrough the arrester assembly to by-pass such surge currents around thecoil and limit the voltage across the coil insulation, and such surgeswill be ineiective to cause a circuit interrupting operation of thebreaker. The arrester assembly herein disclosed utilizes a single seriesporous block and gap of the type shown in the plural series block andgap arrester shown in the patent to L. R. Ludwig, et al., No. 2,135,085,issued November l, 1938. It will be understood that plural series porousblock and gap assemblies may be used with this circuit breaker, ifdesired.

Also positioned beneath the hood portion of the cover assembly is a.tubular sight gauge glass 250, held in position against an integral lug240 on end Wall 45 of the cover assembly, by an apertured threaded plug249, and an indicating rod 252 is slidably mounted through the aperturedplug and tubular sight glass, and is provided with a float 254 securedto the lower end thereof Within casing 2 so that the level of liquidwithin casing 2 may be readily determined from the exterior thereof byinspection of the sight glass beneath the hood portion oi the coverassembly.

Thus, there is provided in a single unit an automatic reclosing circuitbreaker characterized by its ability to automatically maintain thebreaker contacts in an open circuit position in response to faults whichcontinue a predetermined period of time, and by its inverse time currenttripping characteristics with predetermined time delay in reclosing ofthe circuit, together with means incorporated in the unit to protect'the coil insulation and prevent operation of the breaker in response tothe occurrence of surges in the circuit. Moreover, the cover assemblyfor the breaker casing 2 is arranged with a sleet hood portion at oneside thereof to conceal an operating handle which is projected into viewupon lock-open operation of the breaker contacts to indicate thiscondition, and also houses liquid level indicating means, as well asmeans for indicating the number of breaker operations.

Having described a preferred embodiment of this invention in accordancewith the patent statutes, it is desired that it be not limited to theparticular embodiment herein disclosed, inasmuch as it will be obvious,particularly to persons skilled in the art, that many changes andmodifications may be made in this particular embodiment withoutdeparting from the broad spirit and scope of the invention. Therefore,it is desired that the invention be interpreted as lconstitutesupporting means extending into said casing, separable contacts mountedon at least ,one of said members so as to be engaged at one point alongsaid supporting means, at least one `of said members at another pointalong said supporting means dening a side opening, said one memberhaving aligned apertures at opposite sides of said opening, a removablesolenoid coil having a bore, said coil positioned in said opening withthe bore thereof aligned with said apertures, a core guide tubeextending freely through one of said apertures and freely through saidbore into engagement with said one member at the opposite side of saidopening to prevent removal of said coil, a core for said coil mountedfor movement through said tube, said core operatively associated withone of said contacts to actuate the same, and at least another of saidframe members detachably secured to said one member at the end thereofhaving said one aperture and having a portion overlying the adjacent endof said guide tube to prevent withdrawal thereof.

2. In a circuit breaker of the type described having currentinterrupting means including separable contacts, electroresponsive meansfor separating said contacts including a solenoid coil having asubstantially central opening for cooperation with core meansoperatively associated with at least one of said contacts; thecombination of means for unitarily supporting said first two-mentionedmeans including relatively rigidly associated supported frame members,one of said members being of open general U-shape in form for removablyreceiving said coil with the legs oi' said ,U-shaped member beingapertured in alignment with said coil opening, a core guide tube adaptedto be freely insertedv through the aperture in one leg of said U-shapedmember and the opening of said coil to engage the other leg of saidU-shaped member, and detachable means preventing movement of said tubeoutwardly of said apertures comprising means detachably securing anotherframe member to said one leg with portions of said other frame memberoverlying the adjacent end of said tube.

3. In a circuit breaker of the type described having currentinterrupting means including sep arable contacts, electroresponsivemeans for separating said contacts including a removable solenoid coilhaving a substantially central opening for co-operation with core meansoperatively associated with at least one of said contacts; the

combinationof means for unitarily supporting said rst two-mentionedmeans including relatively rigidly associated supporting frame members,one of said members being of open general U-shape in form for receivingsaid coil with the legs of said U-shaped member being apertured inalignment with said coil opening, securing means adapted to be freelyinserted through the aperture in one leg of said U-shaped member and theopening of said coil to engage the other ieg of said U-shaped member forpreventing escape of said coil from said U-shaped frame member, andmeans preventing escape of said securing means outwardly of saidapertures `comprising means detachably securing another frame member tosaid one leg'with a portion of said other frame member overlying theadjacent end of said securing means.

4. In a circuit breaker of the type described having currentinterrupting means including `separable contacts, electroresponsivemeans for separating said contacts including a removable solenoid coilhaving a substantially central opening for co-operation with core meansoperatively associated with at least one of said contacts; thecombination of means for unitarily supporting said first two-mentionedmeans including relatively rigidly associated supporting frame members,one of said members being of open generalv U-shape in form for receivingsaid coil with the legs of said U-shaped member being apertured inalignment with said coil opening, securing means adapted to be freelyinserted through the aperture in one leg of said U-shaped member and theopening of said coil to engage the other leg of said U-shaped member forpreventing escape of said coil from said U-shaped.

frame member, said securing means being unsecured to said U-shapedmember, and means preventing escape 'of said securing means outwardly ofsaid apertures comprising means detachably securing another frame memberto said one leg of said U-shaped member.

JAMES M. WALLACE. HERBERT L. RAWLINS. JAMES M. CUMMING. WAYNE S. ASPEY.

REFERENCES CITED The following references are of record-in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 894,237 Stivers July 28, 19081,180,914 Gengenbach Apr. 25, 1916 1,199,046 Bliss Sept. 26, 19161,336,069 Conrad Apr. 6, 1920 1,394,087 Heinrich Oct. 18, 1921 1,650,799Lee Nov. 29, 1927 2,163,559 MacNeill June 20, 1939v 2,391,277 StapletonDec. 18. 1945

